Highlights comments in bold in an ncurses interface

comment_hili.pl

#!/usr/bin/perl

use strict;
use warnings;
use 5.010;

use Curses;

# Use the name of this program if no file is passed in
my $filename = $ARGV[0] // "comment_hili.pl";

open (my $fh, "<", $filename); # we use lexical filehandles since they have scope

my $win = Curses->new; # Make a new ncurses window and call initscr on it

foreach (<$fh>) {
    # when uses the smart match operator against the topic var to decide when to enter clauses
    when (/#.*/) {
        $win->addstr(substr($_, 0, $-[0]));
        $win->attron(A_BOLD);
        $win->addstr(substr($_, $-[0], $+[0] - $-[0] + 1));
        $win->attroff(A_BOLD);
    }   
    default {
        $win->addstr($_);
    }   

}

$win->refresh;
$win->getch; # wait for user input
endwin;